/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package org.apache.tika.parser.geo.topic.gazetteer;

import java.lang.reflect.Type;
import java.nio.charset.StandardCharsets;
import java.util.List;
import java.util.Map;

import com.google.gson.Gson;
import com.google.gson.reflect.TypeToken;
import org.apache.commons.io.IOUtils;
import org.apache.http.HttpResponse;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.client.utils.URIBuilder;
import org.apache.http.impl.client.CloseableHttpClient;
import org.apache.http.impl.client.HttpClientBuilder;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import org.apache.tika.parser.geo.topic.GeoParserConfig;


public class GeoGazetteerClient {
    private static final String SEARCH_API = "/api/search";
    private static final String SEARCH_PARAM = "s";
    private static final String PING = "/api/ping";

    private static final Logger LOG = LoggerFactory.getLogger(GeoGazetteerClient.class);

    private String url;

    /**
     * Pass URL on which lucene-geo-gazetteer is available - eg. http://localhost:8765/api/search
     *
     * @param url
     */
    public GeoGazetteerClient(String url) {
        this.url = url;
    }

    public GeoGazetteerClient(GeoParserConfig config) {
        this.url = config.getGazetteerRestEndpoint();
    }

    /**
     * Calls API of lucene-geo-gazetteer to search location name in gazetteer.
     *
     * @param locations List of locations to be searched in gazetteer
     * @return Map of input location strings to gazetteer locations
     */
    public Map<String, List<Location>> getLocations(List<String> locations) {
        try (CloseableHttpClient httpClient = HttpClientBuilder.create().build()) {
            URIBuilder uri = new URIBuilder(url + SEARCH_API);
            for (String loc : locations) {
                uri.addParameter(SEARCH_PARAM, loc);
            }
            HttpGet httpGet = new HttpGet(uri.build());

            HttpResponse resp = httpClient.execute(httpGet);
            String respJson = IOUtils.toString(resp.getEntity().getContent(), StandardCharsets.UTF_8);

            @SuppressWarnings("serial") Type typeDef =
                    new TypeToken<Map<String, List<Location>>>() {
                    }.getType();

            return new Gson().fromJson(respJson, typeDef);

        } catch (Exception e) {
            LOG.error(e.getMessage(), e);
        }

        return null;
    }

    /**
     * Ping lucene-geo-gazetteer API
     *
     * @return true if API is available else returns false
     */
    public boolean checkAvail() {
        try (CloseableHttpClient httpClient = HttpClientBuilder.create().build()) {
            HttpGet httpGet = new HttpGet(url + PING);

            HttpResponse resp = httpClient.execute(httpGet);
            if (resp.getStatusLine().getStatusCode() == 200) {
                return true;
            }

        } catch (Exception e) {
            LOG.error(e.getMessage(), e);
        }

        return false;
    }

}
